


Love Isn't Physical Chemistry

by ArielFabulous



Category: One Direction (Band)
Genre: Anal Sex, Angsty Schmoop, Bottom Harry, Chemistry, M/M, Organic Chemistry, Rimming, Rivals to Lovers, Schmoop, Science, Science Experiments, Top Louis, and well the other kind of physical chemistry I suppose..., physical chemistry
Language: English
Status: Completed
Published: 2014-09-05
Updated: 2014-09-05
Packaged: 2018-02-16 06:06:07
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 8,771
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2258622
Author URL: https://archiveofourown.org/users/ArielFabulous/pseuds/ArielFabulous
Summary: <blockquote class="userstuff">
              <p>“Well if it isn’t our resident theoretical chemist Mr. Harry Styles. How is life in the world of the very insignificant and unknowable?” </p>
<p>Harry’s face twitches uncomfortably.</p>
<p>“Hiii Louis. Very good, thanks for asking. How’s everything in the world of...bad-smelling and...erm...explosives?” Harry responds with a smile that is perhaps a touch too bright.</p>
<p>“Thrilling as always. I must say Harold, I am surprised to see you haven’t caught on fire in the sunlight. I thought your kind preferred existing exclusively under fluorescent lighting?”</p>
<p>Harry smiles cooly, up for the challenge. “I bought special sunscreen just for the occasion. And for the thousandth time, my name is not Harold.”</p>
<p>Or; A Science AU where Harry is a physical chemist, Louis is an organic chemist, graduate student life is hard, and solutions to all of life’s problems come from unexpected places.</p>
            </blockquote>





	Love Isn't Physical Chemistry

**Author's Note:**

  * For [ologist](https://archiveofourown.org/users/ologist/gifts).



> Look, I know most of you probably had traumatic experiences in chemistry classes, and think probably science is DIFFICULT and CONFUSING, but I assure you of two things: 1) this fic is MOSTLY witty banter/schmoop/sexytimes and 2) any and all science terminology is probably a clickable link to a picture or wikipedia reference OR explained further in a [bracketed] footnote in the notes after the fic (yes, this fic has footnotes because I am a big fat nerd). Also, as I am a chemist in real life, you may ask me any questions you have about the science in this fic in the comments, and I will do my best to answer them!
> 
> A zillion and one thanks to my beta Tess [Acavall](http://archiveofourown.org/users/Acavall) [Compassanddragon](http://compassanddragon.tumblr.com) for dealing with me through multiple re-writes and time-crunches, you are a gift <3
> 
> All the thank yous go to Leah Snupernope and Ren Loaded-Gunn for running this exchange, especially because I might have asked for a few extensions on completing this fic and they were very understanding and nice about everything!
> 
> I would also like to thank ologist for giving me THE PERFECT PROMPT as I have wanted to write a science AU for ages!!! I hope it’s everything you wanted and more <3
> 
> DISCLAIMER: This entire work is fiction. I made it up. Except the science. The science is real.

It is a beautiful Friday afternoon in May, at the Manchester University chemistry department picnic no less, when Louis Tomlinson’s perfectly constructed life comes crashing down around his ears.

 

It had been all very nice, you see. Louis was in the third year of his doctorate research, already had his masters, and was spending his days (and some of his nights) getting paid (a modest sum) to play with dangerous chemicals all day. He was also had an arrangement for semi-regular feelings-free sex with a certain Mr. Harry Styles, a yeti cherub of a person who was just finishing up his first year of his doctorate. Louis barely held it against him that most of his work was theoretical. It was great. Louis was living The Dream.

 

Except he wasn’t. Because nothing he had done for months was working. Because he was hung up on an un-fixable reaction that literature said would work, just not on _his_ molecules. Because he was just barely clinging to his sanity. Because he felt guilty about using Harry for sex when every single interaction with the boy pointed to the fact that he was a lovely human that Louis did not deserve to interact with.

 

Which is why he found himself outside, in the sun no less, attempting to be sociable with his peers. He squints into the crowd through his glasses, looking for Liam, whose endlessly sunny disposition Louis thoroughly enjoyed spoiling, especially in public. He spots him, holding a blue solo cup, probably full of ice water (poor lad. only one working kidney. what a shame.), talking to Jade (studying biochem? biophysics?). Louis rolls his eyes. The fact that the department wasn’t even cool enough for red solo cups was really just sad.

 

“Liam! Jade! I have arrived! Therefore the party can start--” Louis’s voice dies in his throat. Walking up to the event (Louis will not call this a party, it is not a party, parties are fun.) is none other than Harry Styles. It’s odd seeing him in the sunlight, Louis thinks, as the bright unfiltered rays only seem to make his french vanilla ice cream skin lovelier and his chestnut curls bouncier. His hair is half pulled up in a bun, with the underbits somehow naturally coalescing in alpha helical ringlets that literally bounce as he walks. He was long and lean in dark blue jeans that clung to his legs in a way that made Louis sweat, and a white scoop neck t-shirt with tiny holes in the sleeves.  He smiles and waves to someone he knows, his whole face becoming brighter and his grass green eyes dancing as he lollops over to them.

 

Louis knows that his reaction to seeing Harry has something to do with lots of brain chemicals and millions of years of evolution gone slightly awry (homosexuality does have the slight downside of being unable to produce viable offspring), but there is still a part of him that wants to take Harry apart, piece by piece, and understand why he makes him feel so...everything.

 

Louis has his hypotheses. He wouldn’t call them theories, being untested and all that. It’s not like he could anyway, no reliable control, no isolation of variables. But he knows that the way Harry furrows his eyebrows and purses his lips when he is debugging [Gaussian protocols](http://en.wikipedia.org/wiki/Gaussian_\(software\)) makes him look like a frustrated toddler, which always makes him melt into a puddle. He also knows that Harry has the prettiest cock he has ever seen in person, and he probably thinks too much about how good it feels to have it in his mouth. He knows the way his heart races when he walks down the hidden-unless-you-know-it’s-there back hallway to the small computer lab that houses the special really-fast super-computer that Harry uses to run most of his electron orbital simulations.

 

(“Experiments Louis. They are experiments.”

 

“Yeah yeah okay sure, call them what you like, but they’re really just simulations. I should know, I took a class on quantum mechanics nearly five years ago.”

 

“You are such an arsehole.”

 

“Yeah, but you like my arsehole.”

 

“Mmmm I do indeed…”)

 

Whether or not Louis is in too deep is not up for discussion. The status quo is perfectly acceptable, and he will stick with it. He will do the song and dance if it comes to that.

 

“Heyo Tommo! Back to earth!” Liam snaps in his face, which Louis returns with a death glare that has Liam withering backwards with his hand covering his face. Louis smiles his chimpanzee smile, serving the dual purpose of easing the tension and asserting his dominance, and claps Liam on the back.

 

“Liam, where can a man find an alcoholic beverage at this establishment?”

 

Liam wrinkles his nose in thought, and Louis thinks for the hundredth time how much Liam can resemble a golden retriever.

 

“Well, I’d stick with the cooler, and avoid the punch.” He leans in closer to Louis’s ear. “It’s possible that one of the undergrads already spiked it with ethanol.”

 

Louis clucks his tongue and shakes his head. “That is not only unsafe, but also highly unsanitary. Doubly so if they took it from the solvent shed.”

 

Liam laughs into his cup, but Jade only looks confused.

 

“Why is it worse from the solvent shed?” she asks, which only makes Louis and Liam laugh more. They know full well that the only ethanol in a back closet casually referred to as the solvent shed are the bottles of 200 proof, the high purity stuff that is usually reserved for use on analytical instruments only, and is super expensive[1]. On a person, this would be like chugging everclear or moonshine on an empty stomach. Basically, a recipe for disaster or fun, depending on how you look at it.

 

“People are gonna get sloshed mate.” Liam jabs Louis in the side, which only instigates a minor tickle war, the effect of which has Jade rolling her eyes and walking away.

 

The next half hour proceeds in a similar manner, with Louis and Liam cracking jokes to themselves, gorging on free food and drinks (beer in Louis’s case, and water for Liam), and tracking Harry Styles as he mills about (only Louis does this). When Louis finally does catch his eye, he winks. Harry’s eyes go wide, and he blushes into his beer can. Louis’s heart flutters in his chest, and he decides to go and make him blush more.

 

“Well if it isn’t our resident theoretical chemist Mr. Harry Styles. How is life in the world of the very insignificant and unknowable?”

 

Harry’s face twitches uncomfortably.

 

“Hiii Louis. Very good, thanks for asking. How’s everything in the world of...bad-smelling and...erm...explosives?” Harry responds with a smile that is perhaps a touch too bright.

 

“Thrilling as always. I must say Harold, I am surprised to see you haven’t caught on fire in the sunlight. I thought your kind preferred existing exclusively under fluorescent lighting?”

 

Harry smiles cooly, up for the challenge. “I bought special sunscreen just for the occasion. And for the thousandth time, my name is _not_ Harold.”

 

“What a pity. And here I was thinking that it added a touch of class to your name, which honestly sounds like you should be the male lead in ‘Back Door Sluts 9’.”

 

Harry nearly chokes on his drink, and has to be thwacked on the back a few times by his bleached blonde compatriot in a loose vest and snapback. Louis smiles into his beer can, and waits patiently for Harry to compose himself, loitering in the memory of a few weeks ago when they can amped up the dirty talk to the point where Louis was calling Harry ‘a little slut’ as he fucked him from behind. Harry came so hard that he nearly bit through his lip. It had been a good night.

 

The banter continues, and Harry introduces Liam and Louis to his friend Niall from the Biology department. Louis tries desperately to get to him to taste the punch, but the wool is not so easily pulled over Niall’s eyes.

 

“Uh-uh, no way in hell am I touchin’ that stuff. I could smell the fumes from a metre away. Someone definitely spiked it, and I reckon with something stronger than vodka.”

 

Louis tries not to be too visibly disappointed.

 

The conversation eventually meanders its way around to the topics of their graduate research, as only conversations between four grad students have wont to do. Louis lets Liam and Niall go on and on about their respective projects, Liam dithering on about the [Mitsunobu Reaction](http://en.wikipedia.org/wiki/Mitsunobu_reaction) for far too long, and Niall going on about a specific species of mold only found in the Baltics that could cure cancer. All the while, Harry is unbearably pleasant and engaged in what Liam and Niall have to say. Louis wants to wreck him.

 

Louis finds himself interrupting Liam’s anecdote about something nasty he found growing in a bottle sodium acetate solution. “So Harold, why don’t you tell us about your research? And please don’t tell us you only use that super computer to play Fifa all day.”

 

Both Liam and Niall laugh, but Harry just glares at him.

 

“No I do not use an eight-hundred gigaflop processor to play Fifa. I’m actually working on modelling the outer shell electron clouds of transition block metals--”

 

Louis interrupts him, pretending to snore rather loudly, causing Niall and Liam to giggle. Harry screws up his face into something resembling a petulant toddler, which only spurs Louis on.

 

“Oh I’m so sorry Harold, I just can’t bear to hear academic types talk about nothing at all--”

 

“It’s not nothing Louis, and you know it.”

 

Louis should have just left it there, but he couldn’t. He could see the words on the tip of Harry’s tongue: ‘What have you been doing for the past few months Louis? If nothing you’re doing is working, then it seems like you’ve been doing a whole lot of nothing too!’ He couldn’t let Harry say that out loud, it would only make his struggles too real for him to bear. So, he lashed out.

 

“Oh please. I’m sure you’re just debugging the finer points of someone else’s magnum opus of theoretical chemistry, obviously the work of someone who’s smarter and better at chemistry than you, but just couldn’t write good code.” He sees Harry start to interrupt him but, afraid of what he might be trying to say, Louis barrels on anyway. “All you physical chemists are the same: You’re all either secretly math nerds who couldn’t cut it in the high and mighty world of physics so you have deigned to inflict your mid-level intelligence on the field of chemistry, or you’re computer geeks who took the wrong turn down a hallway and ended up applying their misfired language skills to pure and perfect molecules.” He can see the shock of his words all over Harry’s face, but he can’t stop the insults from tumbling out of his mouth and stabbing Harry like a thousand tiny knives. “Face it Harry, nothing you ever do will be taken seriously by any scientist worth his salt. It’s only a computer model after all, it’s not even real.”

 

Why Louis thought he would feel better after insulting Harry’s entire existence is a mystery, because looking at Harry’s reaction to his tirade feels like a punch to the stomach. Louis doesn’t think he’ll ever forget the hurt etched onto his face, his eye rimmed with tears, or the sound of his accidental sob. He just feels like his chest is on fire, and runs away back into the building to the safety of his lab.

 

He sits at his desk and hugs his knees to his chest for a very long time, waiting for his words to stop ringing in his ears.

 

_Did I really mean all of that?_ Well, yes, because as a laboratory chemist, Louis does believe his skills are superior to all other scientists, engineers be damned[2]. But, no, that doesn’t mean he thinks theoretical types are lazier, or know less. _Fuck, how could I have said that to him? He doesn’t deserve that, nobody does._

 

_I deserve that._ Louis slumps into his knees. _It’s me who deserves to be called out on my shit, not Harry._ He hears the door to his lab creak open.

 

“Louis?” Liam pokes his head in. “What the hell is going on?” If Louis were to look at him, he’s quite sure that he would see Liam’s ‘concerned face’, the one with the little wrinkle between his eyebrows and the slight pout, and he is 100% sure he can’t deal with that right now.

 

“Fuck off Li, you don’t need to say anything, okay, I KNOW.”

 

“Okay, but you should really apologize to Harry--” Liam’s voice sounds small and terrified.

 

“I KNOW. PLEASE GO AWAY,” Louis shouts without turning his head towards the door. He hears the door shut and continues his emotional self-immolation until he decides to head back to his flat after he’s sure the picnic is over and everyone is gone. He’s fine really. Completely fine.

 

He’s not fine at all.

 

 

**Monday Evening:**

 

Just starting material. Again. Fuck.

 

He stares at the computer screen in the [NMR](http://en.wikipedia.org/wiki/Nuclear_magnetic_resonance) room and wishes that world would swallow him up.

 

He spent the whole weekend working on a last ditch effort to make his metal catalyzed [cycloaddition](http://en.wikipedia.org/wiki/Cycloaddition) work (aka not thinking about Harry), and he finally ran the reaction today. He is looking at the spectra of the organic residue of his reaction, and it’s just starting material. The reaction did not happen. Again.

 

Just as Louis begins to consider the logistics of giving up chemistry forever and becoming a hermit in the Scottish Highlands, he hears a knock on the door. He whips his head around to see the stormy face of none other than Harry himself through the glass pane of the door.

 

“Hey Lou. Can we talk?” His voice is muffled by the door and the overbearing air ventilation system required for a room with a 600 megahertz magnet that has to be cooled by liquid helium (so that people can walk close enough to it to deposit their samples inside it safely).

 

Louis feels… well he expected to feel panic, but the nonstop work of the past few days has just made him raw and numb. He nods at Harry, and shuffles over to open the door for him. Harry walks in silently, following behind Louis, who unceremoniously deposits himself back at the computer desk next to [the NMR itself](http://www.pharmacy.arizona.edu/faculty/yanglab/images/NMRFacility/NMR.JPG), with Harry pulling up a spare stool. Louis takes one last look at his spectra.

 

_Just apologize to him you knobhead._

 

“Harry, I am so sorry I said those things to you at the picnic. You didn’t deserve my misplaced anger and frustration, and I--”

 

Harry quickly waves him off.

 

“Louis, you said some incredibly awful things to me on Friday, but I accept your apology. However, that’s not what I want to talk to you about.” Harry goes into the pocket of his stupidly skintight jeans and fishes out a small folded piece of paper.

 

“Oh?” Louis quirks an eyebrow. This is not what he expected at all. Harry clears his throat nervously, and reads from the piece of paper.

 

“Louis, while I have enjoyed the time we have spent together over the past few months, your actions at the picnic have cast into light certain things about our relationship. Or rather, lack thereof.” Louis feels like his chest has gotten tighter. “In the beginning, I was content to keep things simple and uncomplicated, but recent developments have caused me to re-evaluate my priorities, and it appears that they do not equilibrate with yours. Therefore, it is my opinion that we should terminate our arrangement for the benefit of both parties.” Harry lowers the piece of paper from his field of vision, and looks at Louis for his response.

 

“Harry, what. The. Fuck?”

 

Harry rolls his eyes, his mouth twisting as he crumples up the piece of paper and chucks it at Louis, getting up off his chair and threading his fingers through his hair in frustration.

 

“Louis Tomlinson, I am in love with you. You’re literally all I think about, every goddamn day. It’s been affecting my work, and if I’m being honest, I don’t even care. I want to be with you so much Louis. But you treat me like such shit, and you clearly don’t feel the same, and I won’t do this anymore.”

 

Louis can hear the blood rushing through his ears.

 

“Why?” is all he can muster in response.

 

“I wish I fucking knew. But this is clearly another case of me being oblivious to how the people I choose to have sex with really feel about me. That as much as I hated watching you insult me and everything I do, part of me loved it, because at least you were paying attention to me where people could see.”

 

“I’m sorry Harry, I really am, I just--”

 

“No Louis, I already accepted your apology, which is really more than I feel like doing right now. I can’t do this anymore. I can’t and I won’t. I won’t have you talk shit about me and what I do to my face, and then have you come by my lab at ten o’clock at night expecting me to have sex with you. It’s over. We’re done.” Harry walks through the door, and slams it behind him, disappearing down the hallway in a cloud of anger and dark brown curls.

 

Louis sits and stares at the door for a while, trying to remember what it was like before he had a large part of his chest scooped out. He rests his head in his hands and Does. Not. Cry.

 

\---------

 

The next morning, everything goes wrong for Louis.

 

He starts a fire in the lab after leaving out a small piece of Lithium metal he was going to use to make more starting material. Luckily he extinguishes it quickly with a spare bucket of sand, but afterwards, he can’t get his hands to stop shaking. He abandons trying to run reactions, and instead starts restocking his stock solutions, only to forget to put the beaker containing the freshly made 6M NaOH on ice and minorly burning his hand. He also has to hide from Dr. Cowell on at least two occasions, who is passive aggressively badgering him via email and post-its on his desk about his research progress. He even snaps at Liam when he comes by to ask if he wants to grab dinner.

 

The worst part is, even though Louis objectively knows that the events of the day really haven’t been any worse than they’ve been for the past few months, everything _feels_ an order of magnitude worse. He feels eviscerated and empty. Harry Fucking Styles. What a prick.

 

_No Louis,_ he thinks to himself, _you’re the prick. You couldn’t handle a good thing when you had it, and pushed it away when it got too close._

 

Louis is still in the lab around 9pm, still trying to get something done, when he checks the online NMR scheduler to see if he could pop down to get a higher resolution spectra of one of his intermediates. But to his surprise, he sees Harry’s name on the NMR schedule, blocking out all the slots until the next morning. _Cheeky bugger,_ Louis thinks, _probably taking a few thousand scans of some Palladium complex someone else made so he can get some actual experimental data._ He puts his face in his hands and stares at Harry’s name on his laptop screen, going back and forth in his head.

 

_Go down there and tell him how you feel!_

_It‘s not like it will matter at all. He already hates me._

_He might not! At the very least, you’ll feel less shitty about the whole thing._

_Just go down there and stop being a fucking coward._

 

Three minutes later, Louis finds himself knocking on the NMR room door. Harry almost doesn’t let him in, but caves after Louis says please more than several times.

 

“Hey Haz, I’m an hour early,” Louis says, trying to lighten the mood. Harry stares at him for a moment, the hurt in his eyes searing a hole in Louis’s chest, then turns back to the screen.

 

“What do you want Tomlinson?”

 

Louis takes a deep breath, and fixes his eyes on a hole in the carpet a few feet away.

 

_Just fucking do it._

 

“Harry, I want to say that I’m sorry. Sorry again for what I said at the picnic. I just want to explain myself. Why I’ve been treating you like shit and ended up saying those horrible things to you.” He swallows the lump in his throat and continues. “I think I’ve told you a bit about my project in passing, but if you didn’t already know ... it hasn’t been going well these past few months. The cycloaddition reaction that I thought should work refuses to go. And I’ve tried everything I can think of to make it work, but it still isn’t, and … it’s been weighing on my mind a lot lately. So, I guess I just wanted to do something that took my mind off of my shitty frustrating life. And you were around, so I did you.” He cracks a weak smile at his own joke, flicking his gaze over to Harry, hoping in equal parts that Harry will turn around and look at him, but Harry obstinately continues to stare at the NMR computer screen.

 

Louis watches for a moment at Harry hunched over the desk. His shoulder muscles ripple beautifully under his tight sage t-shirt, tight across his shoulders and flowing down to pool delicately at his narrow hips. Louis just wants to be able to touch him again. He looks back at the hole in the carpet.

 

“Except I didn’t expect to like you so much. And I do. I like you quite a lot Harry, and I didn’t realize how much this meant to you, mostly because I didn’t realize how much it meant to me. The past 24 hours have been so shit because...because I knew I couldn’t come back to you. So, it’s a shitty excuse, but that’s why. And I’m sorry. Again.” Finally, Harry spins the chair around. His eyes are fiery, but hopeful.

 

“Do you love me Louis?”

 

“I care about you Harry, more than you know, but--”

 

“You don’t love me.”

 

“I-- I don’t know.”

 

“Could you?”

 

“What?”

 

“Do you think you could love me? If you really mean what you said, and we stopped fucking around, and gave it a real shot, do you think you could love me?”

 

Louis finally looks up from the floor at Harry. God, everything about him is stunning; the cut of his jaw, the pout of his lips, size of his hands, waves of his hair, the small love handles of his hips. He knows the inside of him is just as beautiful too, that he is sweet and kind and caring and smart. He just doesn’t know if _he’s_ good enough to deserve to be with someone like that.

 

“I honestly don’t know. Haz, I hardly have time to eat meals and bathe regularly, let alone sleep. I don’t even have time to get laid. That’s kind of why I started coming to find you in the library late at night. Because I apparently don’t know how to make time in my life for another person. I think I was sick that day of school, you know, the day where they taught you how to have adult relationships. I just don’t know how to do it. I never really learned.” Harry’s expression finally softens, and he chuckles lightly.

 

“Lou that’s okay, it’s not so hard. It’s not even as hard as pchem.” Louis still feels bewildered.

 

“But, how??”

 

“It’s stuff like...making time to have meals with another person, or asking them to hang out with you while you set up reactions, or making plans to spend the day with them. Simple stuff like that.”

 

“And what if it doesn’t work out?” Louis bites his lip.

 

“Then it doesn’t work out. And yeah, that’s shit, but at least you tried. And Lou?”

 

“Yeah?”

 

“I really wanna try with you, but only if you wanna try with me.” Louis swallows and shakes his head.

 

“Haz, I don’t know--”

 

“Look, I need to finish shimming my sample before I start scanning. Give me a few minutes, and think about it.” Harry smiles at him, and turns back to the computer screen.

 

Louis is quiet for a while, running through any and all possible scenarios in his head. So many end badly, with Louis having to avoid Harry in the hallways and at department events. But so many others have him visiting Harry at his desk, playing with his hair, sharing their lunch. Going home together, sharing an apartment, adopting a cat. Even if those things aren’t forever, maybe, just maybe, he wants them.

 

“Okay,” Louis says in a small voice. Harry turns around.

 

“Okay … what?”

 

“Okay. Let’s be in a real adult relationship. Like proper grown ups.” Harry smiles so big that Louis can see his teeth. Even his teeth are lovely and perfect, who even is this kid?

 

“Really?”

 

“Yeah. Let’s make up ridiculous pet names for each other! Let’s scrawl Tomlinson-Styles all over our school notebooks! Let’s file joint tax returns!”

 

Harry just laughs and shakes his head. “Oh Lou, you make it sound like a life sentence in prison. It’s supposed to be fun!”

 

“Fun? Emotional honesty is fun? Harry, I feel like I’ve had several heart attacks in the past 20 minutes. There couldn’t possibly be an upside to that!”

 

“Well,” Harry stands up, and crowds into Louis’s space, taking full advantage of his taller stature, “It does tend to make the sex better…” Harry tucks a stray piece of Louis’s hair behind his ear, and Louis shivers when his finger brushes the outer edge. His fingertips linger on the side of his neck, eventually slotting in on the back of his neck.

 

“Well...I am all for that.” Louis closes his eyes and presses his forehead against Harry’s, his hands automatically coming to rest on Harry’s narrow hips.

 

“Are you sure you want to do this with me?” Louis asks, his voice smaller and weaker that he expects.

 

“Yes.” Harry tilts his head up to press a kiss to Louis’s forehead.

 

“Really really? Are you sure you’ll be able to tolerate me?” Louis means for it to sound sarcastic, but the emotion in his voice makes it sound like a real question. Harry pulls back a bit to give him an appraising look.

 

“Let’s give it six weeks. If we can’t make this work by...July, then we’ll call it off, and that will be that.” Six weeks. Louis can let himself be happy for six weeks.

 

“You’re sure?”

 

“Positive.”

 

Louis lets go of the breath he was apparently holding.

 

“Okay good because I wasn’t sure if you’d even want me around anymore after I said all those awful things to you and mmffftttt--” Louis is cut off by Harry pulling him in by the back of the neck and kissing him full on the mouth. Louis feels warm everywhere, like perfection, like the hole in his chest is finally healing. They kiss inside a [string of time](http://en.wikipedia.org/wiki/String_theory), infinite and instantaneous all at once. Louis passionately presses back, sighing into the kiss, as Harry lightly probes Louis’s mouth with his tongue, pushing inside as Louis opens his mouth for him.

 

Louis starts to want more, and pulls Harry’s hips towards him so that their bodies are completely flush. Harry moans, and Louis walks them over to the wall by the door. He pushes Harry up against it, grinding his hips in rhythm with the push and pull of their kiss, Harry making a high noise in his throat every time their clothed cocks press together. Harry’s hands drop from his shoulders to take Louis ass in both hands, and when he squeezes Louis melts under his touch.

 

_This is what we’re good at_ , Louis thinks, _this is what we know how to do_. He’s already going for the button of Harry’s jeans, when all of the sudden, there’s a single loud BEEP.

 

Both of them freeze. Louis twists his head around, and breathes a sigh of relief. It’s only the oxygen monitor announcing its presence. The oxygen monitor. In the NMR room. Louis is going to have sex in the NMR room. Christ on a cracker, he’s still wearing his lab coat. The lab coat that is covered in stains of god-knows-what. He whips back to Harry.

 

“We can’t fuck--” Harry interrupts him with a wild look in his eyes.

 

“In here, yeah I know it’s--” Louis can’t tear his eyes away from slick and swollen lips and swoops in for another kiss.

 

“--extremely unsafe,” Louis completes. Harry looks at him with dark, love-drunk eyes.

 

“Yeah with the … magnet and the … stuff running … Louis!”

 

Louis pulls his mouth away from the underside of Harry’s jaw, his hands cradling Harry’s head with his fingers threaded through his hair.

 

“Yeah yeah I know. We need to go somewhere else…” He runs through the geography of the building while absentmindedly rubbing his thumbs into Harry’s pulse points on his neck. Harry’s eyes flutter closed, and his mouth part in silent ecstasy. Suddenly, Louis stops rubbing.

 

“Wait, I know where we’re gonna go!” He pecks Harry’s mouth quickly, and takes Harry’s hand.

 

A few minutes later, after pausing in the stairwell for more snogging and groping, Louis is whisking Harry into his lab.

 

“Louis, this isn’t any better! It’s actually probably worse!” Harry exclaims, eyeing the many bottles on shelves. Louis just cackles, whips off his labcoat, throws it in a heap on his desk, and tugs Harry through another doorway.

 

They run through Liam’s lab, and up to another door, where they come to a shuddering halt. Louis turns the handle, and pushes the door open. Harry turns his head to look at Louis, a smile slowly spreading over his face, a smile which Louis returns, his eyes crinkling. He takes Harry’s hand, and pulls him through the doorway, and into the office of Dr. Simon Cowell.

 

The office is a large rectangular room completely lined with full bookshelves and file cabinets, except the back wall which has a large chalkboard covered in random drawings of chemical structures and reaction mechanisms. A small desk with a large black rolling chair is crammed in a corner, but the main centerpiece of the room is a large table that could seat twelve, stacked with piles of papers. Louis wants to fuck Harry on that table.

 

They shed clothes and shoes, sneaking smiling kisses in between, Louis eventually backing Harry up against the table, Harry lifting his haunches to sit on it’s edge, pulling Louis in between his legs. Both of them only in their briefs, and Louis palms Harry through his pants. Louis pulls his mouth away from Harry’s neck and whispers in his ear, “I want to fuck you right here, _right now._ ”

 

Harry whimpers, his hands clawing at Louis’s back.

 

“Oh my god yes, but like...we don’t have any… stuff,” he pants into Louis’s hair. Louis just pulls back and winks. Harry looks half dick-drunk and half stunned as Louis shuffles over to a random file cabinet in the corner of the room, tugs on the bottom drawer, and fishes out a bottle of lube and condoms. Harry’s jaw drops into a surprised smile.

 

“Louis you dirty boy! How long have those been there?” Louis skips back over, smiling cheekily.

 

“A month maybe? It never hurts to be prepared you know.” Louis places the supplies next to Harry and starts tugging at Harry’s pants. Louis needs to touch his dick _right now_.

 

“Lets get these off so I can properly ravish you.”

 

“Hmmm yes please.” Harry leans in for another kiss and tugs his briefs off, letting them slide down his legs, all the while watching Louis tug his own off, his dick hard and curving up to his stomach. Harry stares at it with greedy eyes, his hands unconsciously starting to stroke himself, but Louis bats his hand away.

 

“Uh-uh, that’s my job tonight,” Louis says, taking Harry’s cock in his hands, giving him a few rough jerks, thumbing at the underside of the head like he knows Harry likes. Harry’s hands start going everywhere, moving piles of papers out of the way so he can lie down on the table. Louis runs his hands over his torso, kissing his way down from his perfect pecs to the dark curling hairs of his groin. _Mmmm and to think I was going to give this up_ , he thinks, admiring the view of Harry’s cock, _hard and red and just for me._ He licks a thick stripe up Harry’s dick, and sucks on the head of his cock, Harry writhing and moaning under him.

 

_I could just blow him_ , Louis thinks, _he would definitely like that … but I have something else in mind_. He drops his head lower to tongue at his balls, his hands pressing fingertip bruises into his hips. He pulls his legs apart more, pushing at the backs of his thighs. Harry gets the message, and pulls his knees up to his chest. Louis lowers himself to his knees, and sits back on his heels for a moment to admire the view before pressing his tongue into the small patch of skin between Harry’s balls and arsehole. Harry arches his back as Louis dips his tongue lower to lick over the pink bud of his hole. Harry keens high as the skin flutters under Louis’s tongue.

 

Louis likes doing this for Harry. He knows that it’s really his favorite thing, being eaten out and then fucked. Louis likes it because he can feel and hear Harry coming apart under his fingers and tongue. Louis continues to tongue at his hole, pressing inside with the tip, eventually adding spit and lube slick fingers. When he’s two fingers deep, he finds Harry’s prostate. Louis smiles in wonder as Harry arches off the table, moaning high in his throat. After he adds a third finger for a few pumps, Harry cuts him off in a wrecked voice.

 

“Louis I’m ready, please, I’m close, I need your cock now!”

 

“Alright alright, if you’re sure!” Louis stands up and grabs a condom with his left hand, his right still inside Harry, still shallowly pumping three fingers inside of him. He tries to open it with his teeth, but can’t seem to get it.

 

“Hey here, I’ve g-g-got it,” Harry says, opening the foil square with clean hands and handing Louis the condom. Louis thanks him, rolls it on and slicks himself up. He removes his fingers from Harry’s arse and wipes them off on what he hopes is a pile of scrap paper. Harry sighs at the loss, but Louis quickly lines himself up. He throws Harry’s legs over his shoulders, and slowly presses himself inside with a groan.

 

Louis feels Harry’s tight heat around his cock, and locks eyes with him, Harry’s green irises are reduced to green rings around large dark pupils, dilated from lust. Harry’s long torso is covered in a thin sheen of sweat, and his hair is curling madly and sticking to his forehead. His cock is angry and red, curving up against his stomach, already leaking precome.

 

“You’re so beautiful,” Louis whispers, and leans down to kiss him rough and dirty, Harry’s legs falling off his shoulders to wrap around his waist. He grinds in and out shallowly as he kisses him, subtly changing angle with each thrust until Harry gasps into their kiss.

 

“There, there, right there Lou, jesus!” Harry gasps. Louis pulls his head back a bit and starts driving down into him properly at that angle, hitting his spot almost every thrust, the table creaking in time under them.

 

“Oh God Haz I’m so close. I want you to come with me. Are you close?”

 

“Yes, oh God, yes. I n-n-need you… touch me please!” Louis obeys, reaching between their bodies and starts stroking Harry’s dick, Harry whining in response.

 

Louis watches Harry’s face as he comes, his mouth open in ecstasy as he spurts over Louis’s knuckles and onto his stomach. That tips Louis over the edge, and he thrusts into Harry one last time before shooting his load into the condom. He rides out his orgasm pressed inside Harry, his mind blissfully blank and perfectly sated.

 

\------

 

“Louis, what kind of reaction did you say you were having trouble with?” Harry asks Louis from across the office. They’re both in various states of undress, and trying to clean up after themselves and put Dr. Cowell’s office back in some sort of order before parting ways for the night.

 

Louis walks over to Harry, tugging on his shirt as he goes. Harry is picking up some of the paper piles they shoved onto the floor, and is clutching a stapled packet in his hand. Louis stops to stare at Harry. He’s only wearing his jeans with no shirt (they haven’t found it yet), and the way the silver moonlight from one of the windows is hitting him, he looks like an angel.

 

“Sorry, what did you say?”

 

“The reaction you’re having trouble with, it was cycloadditions, right?”

 

“Yeah, why?”

 

“I just saw an article in one of these piles with that in word in the title. You’ve probably already read it.”

 

Louis furrows his brow, and walks closer. “Maybe not, lemme see.”

 

Harry shrugs and hands him the article, and goes to gather more papers from the floor. Louis scans the article, his eyes getting wider and his pulse picking up as he reads the abstract.

 

“Harry, did you say that this article was in a pile on the table?”

 

Harry looks up from his crouch under the table. “Yeah.”

 

“Well, it’s just that… I’ve never read it before but I recognize the abstract. It’s a paper that was one of about ten I found that I couldn’t access because they were behind a pay-wall. When I asked Simon to purchase the article, he was a real dick about it, and said there wasn’t enough money in his budget to go buying every article that had the word cycloaddition in it.” Louis starts reading the article, and feels his pulse quicken.

 

“Holy shit. That fucking prick!” Louis exclaims.

 

“Aha! Found it!” Harry grabs his green t-shirt that was hanging on the edge of one of the filing cabinets.

 

Louis looks up at him, with excitement in his face. He runs over to Harry, grabs his face in his hands, and kisses him full on the mouth.

 

“You’re amazing, d’you know that?” Harry rolls his eyes fondly.

 

“Well, now that you mention it, I could be reminded more often--”

 

“Oh shut up ya big wanker,” Louis says, swooping in for another kiss. A kiss which turns into a full on snogging session, which is interestingly interrupted by Harry yawning into a kiss. Louis playfully shoves him off. “Alright alright, no second round tonight, I get it.”

 

Harry starts to protest, but only starts to yawn again, which Louis finds delightful because Harry looks like a cat when he yawns.

 

“M’sorry it’s a school night! Can you blame me?”

 

Louis just laughs and checks the clock on the wall.

 

“Harold, it is early yet, “Louis scoffs. “It’s only nearly eleven! Plenty of time for...more...” at which point Louis yawns too, big and loud. It’s now Harry’s turn to laugh, so they’re just both laughing and holding each other. They eventually slow down, Harry just holding Louis, with the older boy’s head tucked under his chin.

 

“Louis?”

 

“Yeah?”

 

“You gonna grab your trousers from Simon’s chair before you go home?”

 

“Nah, I thought I’d go without. Leave them there as a thank-you gift for so graciously letting us use his office in a time of need.”

 

“It was rather nice of him.” Louis hums in approval, and sways with Harry for a few more minutes, enjoying being enveloped by his warmth for as long as possible.

 

“Harry?”

 

“Mmmm?”

 

“We should probably go.”

 

“Yeah, I know.” Harry releases Louis from his embrace, Louis pecking him on the lips before walking over to Simon’s massive office chair and grabbing his jeans.

 

“Condoms and lube safely stowed?” Harry asks, standing in the doorway back to the lab.

 

“Yup! Oh um--and the thing you found--” Harry waves the paper packet in his hand.

 

“Right here darling.” Louis quickly pulls the jeans on, and they walk out of the office together. Louis doesn’t drop the article off at his desk, and instead keeps it. _Maybe it will be a good bedtime story_ , he thinks, waving to Harry as he walks off towards his car.

 

\-------

 

The next day around noon, Louis bursts into Harry’s office, and attacks him from behind. Harry splutters and pulls out his headphones to see Louis hugging him from behind his swivel chair and pressing kisses all over his hair and face. He turns the chair around, laughing as he pulls Louis into his lap, Louis continuing to pepper kisses all over his face. At this point, Harry finally catches the words Louis is saying in between every kiss: “thank you thank you thank you”. Louis finally pulls back and fixes Harry with a warm but serious look.

 

“Thank you Harry. Thank you so so so so so much. For… everything, I just--” He seems overcome and leaves the phrase dangling. Harry just grins cheekily.

 

“Can I be expecting this sort of ‘thank you’ every day after we have particularly good sex?”

 

Louis grins and cuffs him about the head, but with little force behind it.

 

“I’m not just talking about the sex you insufferable doof. The article you found in Cowell’s office last night? I read it last night, and it basically describes why none of my cycloadditons have been working. I was thinking about it too closely, like paying too much attention to the leaves on the trees when I needed to see the forest or something.” Harry nods along, at the very least, simply content to watch Louis be excited and adorable. “So, essentially, the article basically detailed why all the catalyst types I’ve been using are completely wrong for my substrate, and I should have been using ligands that donate electron density to the metal center, not withdraw.” He paused for a moment, shaking his head. “Then, I remembered. _We_ talked about it. I was complaining to you about my problems with the cycloaddition, saying that I wasn’t even sure it was thermodynamically possible, even at temperatures attainable in a lab. And you said you’d check if I sent you the structures of all the reagents, which I did, and within a day you said you’d done the math, and that it should be possible, and that I should keep messing with the conditions of the reaction. That the reason it wasn’t working probably had to do with something else related to the catalyst.”

 

The lights go on in Harry’s brain and he nods along. “Oh yeah, now I remember. I liked doing that. It was rather soothing actually.”

 

“You find doing hours of math soothing? Who even are you?”

 

“I am a physical chemist. It’s what I do.”

 

“But soothing?”

 

Harry shrugged.

 

“It was a break from what I normally do all day, which is essentially making shit up and seeing if it fits within the parameters of physical reality. Which, as it turns out, at a quantum level, physical reality tends to be rather difficult to define.” He shrugged again, “It was a problem with a clear questions and clear path to the answer. Just some good old-fashioned number crunching, something I happen to be very good at. It was my pleasure.”

 

Louis just looks at him with a soft smile. “Still Haz, you pointed me in the right direction ages ago. Why didn’t I listen to you? I’m such an idiot.” Louis drops his head into his hands, but Harry pulled them down, and held them in their lap.

 

“No you’re not. You weren’t ready to hear it yet. And besides, at that time, you still hadn’t ruled out other stuff, am I right?”

 

“Yeah, I s’pose. Still makes me pretty thick though.”

 

“Definitely. But here, listen to me. You want to know the craziest thing about what I do? In all of quantum mechanics, in all the math and all the physics and all the formulas, we really only _know_ the wave function for the hydrogen atom. That’s it. Everything else we make up as we go along. It’s all approximation after approximation. We improvise. Except for a few choice physicists who did get it right occasionally. That guy who proved that energy is always equal to the mass times the speed of light squared wasn’t fucking around--”

 

Louis is already squeezing his hands impatiently. “Get to the point Haz.”

 

“We don’t have to know what we’re doing all the time, we just have to know the important stuff. We’ll figure it out, and we’ll make it work. We’re scientists. That’s what we do. And if you don’t make mistakes--”

 

“You’re doing it wrong. Yeah yeah I know that one.”

 

“Really? You know that quote too?”

 

“Course. It was framed in big bold letters in my gen chem lecture hall. SCIENCE: If you don’t make mistakes, you’re doing it wrong. If you don’t correct those mistakes, you’re really doing it wrong. If you cannot accept that you’re mistaken--”

 

“Then you’re not doing it at all. Yeah I know it. I’ve got it on a post-it I keep by the super-computer that runs Gaussian.”

 

“Mmmhmmm. I do love a good science platitude. Another good one: a scientist is always fine. That is the first thing a scientist is.[3]”

 

“Hmm yes, I quite like that.”

 

“Yeah. Super fiiiine.”

 

“Cheeky bugger.”

 

“Love you.”

 

“Me too.”

 

**SIX WEEKS LATER:**

 

Text from “Loubear”: Meet me in my lab at 6 ;)

 

Harry glances at the time on his phone (5:45) and starts packing up his stuff, first checking that the rendering of the electronic surface simulation is still running on the desktop computer in his tiny cramped office. _Should be finished by Christmas if I’m lucky_ , he quips to himself, shoving his laptop and a few folders into a small black rucksack. He listens to [music](https://www.youtube.com/watch?v=yzwu4vms9nM) as he makes his way to the other end of the chemistry wing, humming along when he can.

 

When he gets to Louis’s lab, he expects to find him puttering about in front of his benchtop, or fussing with something in the chemical hood, the place a complete tip (“All the important parts are clean Harold, it just _looks_ messy! Trust me, I know where everything is, and that’s what matters.”). Harry has many favorite Louis moments, but his real favorite is watching him in lab, completely in his element, a little golden mousling scurrying about in a heavily stained labcoat, doing everything in a precise order and procedure only known to him (“But Lou, why do you add the starting material last?” “Because if I don’t, the reaction doesn’t work. Don’t look at me like that, I don’t make the rules!”).

 

But that is not what he finds today. The lab is spotless, completely empty, and the floor is covered in … rose petals?? Harry shakes his head, smiling like he can’t believe how he got this lucky.

 

He follows the trail of pink petals all the way through Liam’s lab up to a very familiar door. Harry aims to say something witty and cheeky, but all that comes out is a very watery and overcome “Louis?”

 

“Right here babe.” Louis is sitting on the table in Simon’s office, which has been miraculously cleared, and is only set with some electric candles and a picnic basket. Louis looks at him with shining blue eyes, decked out in a black blazer and one of his band shirts, complete with requisite skinny jeans and his Vans. He’s holding four pieces of paper fanned out in his hands, and smiling proudly.

 

“Louis a-are those what I think they are?” Louis just smiles bigger.

 

“Well, if you think they are a proton NMR spectrum, a carbon-13 spectrum, a GC mass spec, aaand,” he shows Harry the last page with a flourish, “An extra fancy COSY 2D NMR spectrum[4]. Then yes, I have confirmed synthesis.”

 

Harry drops his rucksack, closes the distance between them in two long strides, removes the papers from Louis hands, and delicately places them in a pile on the table. Then, he proceeds to scoop him into a crushing hug.

 

“ ‘m so proud of you. I love you so much,” Harry says against the crook of his neck.

 

“I know. I love you too. Thank you,” Louis says, his voice only breaking a bit at the end. They stay like that for a while, until…

 

 

“Harry, you know that this reaction was only step ten out of eighteen, right?”

 

“LOUIS!”

 

_fin_

 

Footnotes:

[1] I kind of really just wanna say that 200 proof alcohol, aka 100% pure ethanol, is actually really interesting because it’s nearly impossible to distill to that high of a purity. It’s because of the azeotropic effect between water and ethanol that makes its really hard to generate any purity above 95% ethanol to 5% water, and chemists have to do crazy shit with pressure to pull off those last few percent of water, as well as use weird reagents to absorb the last bit of water. Basically, I think the chemistry of liquor and spirits is really cool and I like to talk about it at parties and have people give me weird looks.

[2] Chemists and Chemical Engineers are fundamentally different types of people, and are like oil and water, if oil and water were forced to be like peanut butter and jelly. They don’t really mix very well, but they need each other sometimes. I just wanted to put that out there.

[3] Yes, this is a Welcome to Night Vale quote. No, I am not sorry.

[4] I could include a litany of links to what each of these kinds of spectra are, and why they’re necessary to “confirm synthesis”, but I’ll just summarize it here.

The proton NMR spectrum, which essentially shows how many and what kinds of unique hydrogen atoms are in your molecule (it is WAY more complicated than that, but thats the quick explanation) can be used to confirm synthesis because every molecule has a unique proton NMR spectrum (except in cases of [enantiomers](http://en.wikipedia.org/wiki/Enantiomer)). Gas Chromatography/Mass Spectroscopy, more colloquially referred to as GC/MS or just Mass Spec, is the isolation of your compound by boiling point (this is the GC part, of which I am also simplifying to a nauseating degree), and then shooting electrons at your molecule which breaks it into pieces in a predictable pattern (the Mass Spectroscopy part, which is actually pretty accurate), which can be analyzed to confirm synthesis. Basically, it should give you the molecular weight of your compound, which alone doesn’t confirm synthesis, but in combination with a proton NMR spectrum, confirms synthesis. The carbon NMR is the same thing as a proton NMR, but with carbon molecules instead of hydrogen molecules. However, Carbon NMRs take longer to get decent spectra (a proton NMR takes 15 minutes, a carbon NMR takes like an hour and a half), and only work well on really pure samples, which is why if you want to say in a published paper that you made this molecule, you need a carbon NMR to really really say for sure that you made the thing. Finally, a COSY 2D NMR spectra is a special kind of proton NMR that, in simplified terms, shows the relationships between your unique protons that are near each other. A COSY shouldn’t tell you much more than you already know from a proton NMR, and can take a while, but they are [very pretty](http://www.chem.sci.ubu.ac.th/inmr/nmr/pictures/2dnmr/cosy_ipsenol_dqf.gif), and can show differences between enantiomers in some cases. **TL;DR: Louis is being a little show-off by having all four of these kinds of spectra.**

**Author's Note:**

> MWAHAHAHA now that my identity has been revealed, I can now point you in the direction of how to contact me outside of AO3 should you choose to do so! My main fandom blog is [arielfabulous](http://arielfabulous.tumblr.com) and my one direction sideblog is [thesefiveidiots](http://thesefiveidiots.tumblr.com). THANK YOU FOR READING MY FIC!


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